15" Jubilee Design

[jwc]

There is a way to make that work. But you would do it differently than what you are suggesting.

For a moment.......keep the design as is. Remove the idea of placing woofers (dual 12" K31's) where they are now.

Now....in that woofer chamber...don't put the "slots" where they are now. Instead......put them on the front panel. Make them 5 x 10" instead of 5 x 9". Then turn the "splitters" around. The ramps will have a different flare than the one now and that is easy to modify.

Now just make an enclosure on the front panel. Now your dual 15's will "fit" w/o changing the horn.....

The thing you also need to do......is make a chamber connection between where the 15" woofers are now and where the 12" woofers used to be. This will allow more air space requirements for the 15" woofers so that they will "annul" below 40Hz.

There are some pricy 15" woofers out there that will "work" on a 50 sq in throat (x2) and will work in that air space requirement.

I've drawn this out before and on paper "it works".

Thing is...after doing this type of thing out on paper several times.....it comes to a point of just redoing the whole thing from scratch.

Since.....I've drawn up some designs with 2 15" woofers with the same footprint as the jube (w/o the nose) that is a 35 Hz horn 1/8th space and has an internal horn path about 15-20 inches longer than the jube. I'm building it now. My concern is how high up it will go....as the fold pattern is complicated.

BUT....no reason to try what is suggested above.....if you are into cuttin some woold for the heck of it and see what you get...

jc

[PrestonTom]

JC, I am curious about what you are up to, but I can't understand what you have described. A picture would be worth a thousand words. Even a rough sketch.

I also agree about the difficulty of making a two-way system. It really limits your choices, unless the Original Poster is willing either to give up the HF extension or to give up the low freqeuncy extension. If you abandon the lows, then you will need to do some explaining to Dr Who and JC (insert smiley face here)

[jwc]

.....

[infurno]

.....

That's a very interseting idea, but there is a problem in your illustration.

First, I'm no expert and someone please correct me if I'm wrong but I believe your addition to the front horn element will interact with the wave in very strange ways creating nonuniform directivity and many other problems.

Second, your illustration is a modification of an already modified design:

Just to make sure there is no confusion, I'll go over the current design state:

The original La Scala plan:

Here is the modification currently considered:

The only changes are marked in red. The interior chamber and cabinate is stretched by 3 inches, leaving all other horn dimensions identical to the original design.

[jwc]

To do what I'm suggesting....you do not need to widen. My drawing is a "hack" not meant to be of any scale. I realize what you had up there.....I borrowed it to explain a point only of where to put the woofers, turning around the splitter, and putting on the additional woofer chamber.

""""The only changes are marked in red. The interior chamber and cabinate is stretched by 3 inches, leaving all other horn dimensions identical to the original design.""""

yes...I realize what you have done. So how large is the thoat for that horn?

jc

[jwc]

I would be interested to know what the total throat size is for what you suggested.

Then....what the horn "width" is at certain points along the horn circled in red. You have provided some.

Then what would be the total depth of the entire horn. It aint gonna be 24". It will be much deeper and wider to accomidate what looks like a slot (throat) width of 6 inches on each divided horn.

I like the idea of what you are doing. This idea has been discussed before. In the end......I think just starting from scratch is better. But my experience with using that "style' of horn path with two 15' woofers....leads to a big cabinet.....but hey...what is wrong with that.....if you like big

jc

[jwc]

If you kept the throat size the same with the above but just widen 3 inches......then that looks like it "would work". However, it might be tough to find a 15" woofer that will work in that throat size AND annul 40Hz or below at about ~36 liters.

I like that drawing....

jc

[jorjen]

If you are interested in using dual 15's, why not just build the Jamboree?

[jwc]

Yep. Way easier too. I only wish the horn path was longer on it.

jc

[Rudy81]

Yep. Way easier too. I only wish the horn path was longer on it.

jc

Any chance of modifying the Jamboree to make the volume what you wish? I'd love to hear more on that.

[PrestonTom]

Personally, before I would start a Jamboree project I would want to have a look at some measures of freq response & efficiency/distortion. It may be a fine cabinet, but there are some unknowns (eg. does it go high enough so that it can be used in a two way system - if that is important ...).

Starting from scratch is always a possibility, but we know that the Jubilee works. So that always makes it a good starting point.

Has the OP had an opportunity to hear a Jubilee? I have a garage built version (a faithful rendering IMHO) and I think it sounds pretty darn good ... even if it only has 12 inch drivers.

[jwc]

For the "keeping everything the same" except for the 3" width expansion.....

this woofer will work from a T/S calculation pretty good.....

http://www.bcspeakers.com/product.php?id=68

Will annul 40Hz or less but the driver is rated down to 40Hz only.........

So if you wanted the horn path of the Jube with dual 15" power......

jusy spittin out stuff here....

jc

[jwc]

Yep. Way easier too. I only wish the horn path was longer on it.

jc

Any chance of modifying the Jamboree to make the volume what you wish? I'd love to hear more on that.

I'm not concerned with the woofer chamber volume......just path length. I'm not saying this is a problem....just something I would want. The Jube path is 55"...the Jamboree I think about 40". Khorn is greater than 55" if I remember. I drew up a basshorn with the footprint of an MWM but 1/4th space instead of 1/2 space.......I didn't have the guts to build it.

You want to extend the length of the Jamboree.....then you are now at a depth of a 30" plus cabinet. The Jamboree is good. I'm just speaking in principles depending on what you want. Heck....build a straight axis bass horn and go two way with a tap horn sub..... Then this whole subject really becomes academic.

challenge to the group....

Come up with a 38-40Hz 1/8 space bass horn with the footprint of the khorn or jube with a path length of 55" or better......with the goal to get out to 400Hz plus......That is where it gets hard.....real hard....

jc

[infurno]

Sorry about the delay, had to catch up on some work.

The Jamboree is a pretty radically different design and has
little to
nothing to do with Klipsch or Jubilee. For example, it only has 1 fold
and a shorter path as already pointed out. The Jubilee seems like a much

better proven and refined design and I think a 15" Jubilee would be more
unique and interesting than a Jamboree. Not to mention the Jubilee is
much better documented and the plans are easier to come by. (I have not
yet seen plans for a Jamboree, but I'm familiar with the horn layout)

[jorjen]

I agree with the points you are making and brought up the Jamboree as a point of interest and another direction to consider. I am almost finished with a pair of Jubilee clones myself and could not be more enthused and excited.

Greg Roberts I believe is the only forum member to have both the Jubilee and the Jamboree(can't remember if JWC tried them both or not) and has stated openly on the forum that he prefers the Jamboree. Food for thought, every ones tastes differ. I realize it is not a Klipsch design and believe me when I say no one on this forum is less fond of that idea than myself. But, let us not forget that performance is the bottom line. The Jamboree as a design concept is absolutely worth some consideration in my opinion, but it is just that, my opinion. Accurate plans are also extremely easy to obtain or at least they used to be.

As far as Jubilee plans are concerned, I believe I used what would probably be considered the most reliable/accurate plans available outside Klipsch facilities and there still exists some speculation as to their absolute accuracy. No 100% guarantees either way.

Fun stuff, eh?

[jwc]

"""""can't remember if JWC tried them both or not"""""

Yep....had them both at the same time.

jc

[ClaudeJ1]

You could use stock LaScala split bass bins as the core.

Perhaps we should back up a bit and find out what the guy is trying to accomplish. IOW, what are the goals.

The La Scala is a simple build, but the low freq extension is limited (short path & undersized mouth) since it is basically a 100-125 Hz horn. Its high freq is limited because of the driver (partly) and the folding (mostly - I think).

If size is not a problem and you can can live with a 40-50 Hz low end, then a simple build would be to follow Dtel's lead and make a MWM. This is a simple build, however it is a big boy and may still require a sub depending what your goals are.

What is it you are up to? Three-way or two way? Deep bass?

Or, if you want a version that neatly fits in a corner and uses 40% less floor space (no dead air behind the cabinets), you could build 2 or 4 of my Quarter Pie Horns, the build 4 Spuds to get you down from 60-17 Hz.

https://community.kl...hornresp/page-1

[ClaudeJ1]

why would anyone think they can just step in and change the sizes of the cabinets and expect the speakers to work correctly.

Because we have several things at our disposal that were not availble cheaply 30 years ago. We now have the equivalent of $20,000 worth of test gear for less than $500. REW and other software is free, as is Hornresp. We have a solid base of Do It Yourself fanatics with great knowledge and skill who are willing to share openly, that's why. Any other questions, hombre?

[ClaudeJ1]

There is a way to make that work. But you would do it differently than what you are suggesting.

For a moment.......keep the design as is. Remove the idea of placing woofers (dual 12" K31's) where they are now.

Now....in that woofer chamber...don't put the "slots" where they are now. Instead......put them on the front panel. Make them 5 x 10" instead of 5 x 9". Then turn the "splitters" around. The ramps will have a different flare than the one now and that is easy to modify.

Now just make an enclosure on the front panel. Now your dual 15's will "fit" w/o changing the horn.....

The thing you also need to do......is make a chamber connection between where the 15" woofers are now and where the 12" woofers used to be. This will allow more air space requirements for the 15" woofers so that they will "annul" below 40Hz.

There are some pricy 15" woofers out there that will "work" on a 50 sq in throat (x2) and will work in that air space requirement.

I've drawn this out before and on paper "it works".

Thing is...after doing this type of thing out on paper several times.....it comes to a point of just redoing the whole thing from scratch.

Since.....I've drawn up some designs with 2 15" woofers with the same footprint as the jube (w/o the nose) that is a 35 Hz horn 1/8th space and has an internal horn path about 15-20 inches longer than the jube. I'm building it now. My concern is how high up it will go....as the fold pattern is complicated.

BUT....no reason to try what is suggested above.....if you are into cuttin some woold for the heck of it and see what you get...

jc

15-20 inches longer than the original Jube would certainly improve the low end and make it go lower than a Khorn for sure. Both the Jube and Khorn roll off quite a bit at 60 Hz. based on my measurements, but the Jube has much stronger bass output between 60-120 hz. where it counts vs. the Khorn, and why many prefer it. At 3.5 feet long, the Jamborree is a shorthorn, in my opinion, (and simulation about 80 hz. cutoff) so, like a Jubilee, relies HEAVILY on a corner for it's bass extension. The best measuring and sounding horn above 45 Hz. is the MWM at 6 feet. My 5 foot Quarter Pies have very similar sound and measurement with about 10 Hz higher cutoff and has only ONE 90 degree fold instead of all this fancy folding. Straight Axis horns sound the best, but impractical for bass, so, for me, the fewer folds, the better. As I recall, the Jube is about 4.6 feet long so adding 20 inches would make a HUGE difference in the low end by extending it by 15 Hz.. 2 and 3-way Theater Jubes cross at 500 and 400 hz. respectively and even though the curves show a response above 1 Khz., things are pretty funky up there coming out of a bass bin anyhow. So I don't think it's a cause for much worry.

Edited May 12, 2014 by ClaudeJ1

[seti]

Time travel?